Advances in the biology, diagnosis and host-pathogen interactions of parvovirus B19

Rheumatic manifestations and sequela of acute parvovirus B19 infection in hospitalized adult population

BACKGROUND

Parvovirus B19 infection has been associated with various clinical entities including musculoskeletal manifestations and the development of different autoimmune diseases. The aim of our study is to examine the musculoskeletal manifestations associated with acute parvovirus B19 infection and the possible development of chronic autoimmune rheumatic diseases.

PATIENTS AND METHODS

Retrospective cohort study that included adult hospitalized patients diagnosed with an acute parvovirus B19 infection between 1 January 2021 and 1 February 2024. Subjects were followed-up for 6-12 months after hospitalization aiming to identify patients who developed chronic autoimmune rheumatic diseases.

RESULTS

The study included 23 patients diagnosed with acute parvovirus B19 infection. Patients were predominantly females (16, 69.6%) with mean age at diagnosis of 39.3 ± 13.11 years. Most patients were Jewish (15, 65.2%). The two most common acute symptoms were fever (82.6%) and myalgia (56.5%). Polyarthritis was present only in three patients (13%) and all of them had wrists involvement. Anti-nuclear antibodies and rheumatoid factor were the most common autoantibodies present with equal prevalence each (13%). Five patients were treated with prednisone during the acute phase (21%), two (8.7%) of them needed drug escalation and were subsequently treated with hydroxychloroquine and methotrexate. One patient developed systemic lupus erythematosus during the first 6 months of follow-up.

CONCLUSION

Musculoskeletal manifestations developing during acute parvovirus B19 are usually self-limited with only a small minority of patients developing chronic autoimmune diseases. It is crucial to differentiate self-limited manifestations related to acute parvovirus B19 from idiopathic autoimmune diseases aiming to avoid unnecessary immunosuppressive therapy.

Seroprevalence and Associated Outcomes of Parvovirus B19 Infection in Human Immunodeficiency Virus Patients: A Systematic Review

Several case reports have highlighted the presence of serious clinical outcomes in patients with human immunodeficiency virus (HIV) related to parvovirus B19 (PVB19). However, epidemiological studies have produced inconsistent and varying results regarding the prevalence of PVB19 and its associated clinical outcomes in this population. These inconsistencies highlight the need for a thorough summary and analysis of present data to better understand burden and impact of PVB19 on HIV patients. This review aims to provide an overview of current evidence and identify areas for further research. Following the Meta-analyses of Observational Studies in Epidemiology (MOOSE) guidelines, a comprehensive search was conducted across Medline/PubMed, Google Scholar, and World Health Organization Virtual Health Library Regional Portal. The pooled prevalence with the corresponding 95% confidence interval (CI) was measured using Comprehensive Meta-Analysis Software version 3.3. Publication bias was estimated based on Begg's test, Egger's test, and examination of the funnel plots. A total of 16 studies, with 2,122 HIV patients, were included in the meta-analysis. The pooled prevalence of detecting anti-PVB19 immunoglobulin G, anti-PVB19 immunoglobulin M, and PVB19 DNA particles among HIV patients was 43.6% (95% CI: 23.5-66.1%), 5.10% (95% CI: 2.10-12.10%), and 6.40% (95% CI: 4.10-9.90%), respectively. In the overall population of HIV patients, most of the included studies did not establish a statistically significant association between PVB19 infection and the occurrence of anemia. PVB19 infection is commonly detected in individuals with HIV. However, anemia due to PVB19 is not common in this population. Findings from a few studies suggest that PVB19 infection may contribute to anemia in individuals with advanced HIV disease or significant immunosuppression. Additional research is needed to confirm and clarify these relationships in individuals with HIV, particularly those with compromised immune systems.

Erythema Infectiosum: A Narrative Review

BACKGROUND

Erythema infectiosum occurs worldwide. School-aged children are most often affected. Since the diagnosis is mainly clinical, physicians should be well-versed in the clinical manifestations of erythema infectiosum to avoid misdiagnosis, unnecessary investigations, and mismanagement of the disease.

OBJECTIVES

The purpose of this article is to familiarize physicians with the wide spectrum of clinical manifestations and complications of erythema infectiosum associated with parvovirus B19 infection.

METHODS

A search was conducted in July 2022 in PubMed Clinical Queries using the key terms "Erythema infectiosum" OR "Fifth disease" OR "Slapped cheek disease" OR "Parvovirus B19". The search strategy included all clinical trials, observational studies, and reviews published within the past 10 years. Only papers published in the English literature were included in this review. The information retrieved from the above search was used in the compilation of the present article.

RESULTS

Erythema infectiosum is a common exanthematous illness of childhood caused by parvovirus B19. Parvovirus B19 spreads mainly by respiratory tract secretions and, to a lesser extent, the saliva of infected individuals. Children between 4 and 10 years of age are most often affected. The incubation period is usually 4 to 14 days. Prodromal symptoms are usually mild and consist of lowgrade fever, headache, malaise, and myalgia. The rash typically evolves in 3 stages. The initial stage is an erythematous rash on the cheeks, with a characteristic "slapped cheek" appearance. In the second stage, the rash spreads concurrently or quickly to the trunk, extremities, and buttocks as diffuse macular erythema. The rash tends to be more intense on extensor surfaces. The palms and soles are typically spared. Central clearing of the rash results in a characteristic lacy or reticulated appearance. The rash usually resolves spontaneously within three weeks without sequelae. The third stage is characterized by evanescence and recrudescence. In adults, the rash is less pronounced than that in children and is often atypical. Only approximately 20% of affected adults have an erythematous rash on the face. In adults, the rash is more frequently found on the legs, followed by the trunk, and arms. A reticulated or lacy erythema is noted in 80% of cases which helps to distinguish erythema infectiosum from other exanthems. Pruritus is noted in approximately 50% of cases. The diagnosis is mainly clinical. The many manifestations of parvovirus B19 infection can pose a diagnostic challenge even to the best diagnostician. Complications include arthritis, arthralgia, and transient aplastic crisis. In most cases, treatment is symptomatic and supportive. When parvovirus B19 infection occurs in pregnant women, hydrops fetalis becomes a real concern.

CONCLUSION

Erythema infectiosum, the most common clinical manifestation of parvovirus B19 infection, is characterized by a "slapped cheek" appearance on the face and lacy exanthem on the trunk and extremities. Parvovirus B19 infection is associated with a wide spectrum of clinical manifestations. Physicians should be aware of potential complications and conditions associated with parvovirus B19 infection, especially in individuals who are immunocompromised, chronically anemic, or pregnant.

Intrauterine Blood Transfusion for Parvo B19-Induced Fetal Anemia: Neuroimaging Findings and Long-Term Neurological Outcomes

INTRODUCTION

We aimed to evaluate the neuroimaging findings and long-term neurodevelopmental outcomes of fetuses and children following intrauterine blood transfusion (IUT) for parvo B19 infection-induced anemia compared to those with RBC alloimmunization.

METHODS

We conducted a retrospective cohort study including women who underwent an IUT due to fetal anemia between 2006 and 2019 in a tertiary, university-affiliated medical center. The cohort was divided into two groups: a study group - fetuses affected by congenital parvo B19 infection; and a control group - fetuses affected by RBC alloimmunization. Retrospective data such as antenatal sonographic evaluations, fetal brain MRI results, and short-term fetal and neonatal outcomes were collected. All children underwent a neurodevelopmental evaluation after birth using a Vineland questionnaire. Primary outcome was defined as the presence or absence of neurodevelopmental delay. Secondary outcome was defined as the presence of abnormal fetal neuroimaging findings such as cerebellar hypoplasia, polymicrogyria, intracranial hemorrhage, or severe ventriculomegaly.

RESULTS

Overall, 71 fetuses requiring at least one IUT were included in the study. Of these, 18 were affected by parvo B19 infection and 53 by RBC alloimmunization with various associated antibodies. Fetuses in the parvo B19 group presented at an earlier gestational age (22.91 ± 3.36 weeks vs. 27.37 ± 4.67 weeks, p = 0.002) and were more affected by hydrops (93.33% vs. 16.98%, p < 0.001). Three fetuses out of the 18 (16.67%) fetuses in the parvo B19 group died in utero following the IUT. Abnormal neuroimaging findings were detected in 4/15 (26.7%) of the parvo B19 survivors versus 2/53 (3.8%) of fetuses affected by RBC alloimmunization (p = 0.005). There was no difference in long-term neurodevelopmental delay rates between the children in the study and control groups, as assessed at the average age of 3.65 and 6.53 years, accordingly.

CONCLUSION

Fetal anemia due to parvo B19, treated with IUT, might be associated with increased rates of abnormal neurosonographic findings. The correlation between those findings and long-term adverse neurodevelopmental outcomes requires further investigation.

Acute Onset of Remitting Seronegative Symmetrical Synovitis With Pitting Edema (RS3PE) Two Weeks After COVID-19 Vaccination With mRNA-1273 With Possible Activation of Parvovirus B19: A Case Report With Literature Review

Remitting seronegative symmetrical synovitis with pitting edema (RS3PE) is a rare clinical entity characterized by “remitting,” “seronegative,” and “symmetrical” synovitis with pitting edema on the dorsum of the hands and feet. Although rheumatic or malignant diseases are diseases that are known to coexist with RS3PE, other factors such as medication, infection, and vaccination have been reported to be associated with RS3PE. Here, we present a case of RS3PE syndrome that satisfied all four diagnostic criteria of RS3PE (pitting edema in the limbs, acute onset, age ≥ 50 years, and/or rheumatoid factor negativity) after mRNA-1273 SARS-CoV-2 vaccination.

Assessment of human parvovirus B19 infection in Egyptian hemodialysis patients

INTRODUCTION

Parvovirus B19V has been shown to be associated with end-stage renal disease (ESRD) with increased risk of post-infection anemia, especially in hemodialysis (HD) patients. This effect may be due to immunosuppression, insufficient erythropoietin, or short lifespan of red blood cells. Therefore, parvovirus infection should be investigated in this group of patients suffering from anemia or pancytopenia. We assessed the frequency of parvovirus B19 in HD patients attending Suez Canal University Hospital and analyzed the correlation of this infection with hematological parameters in those patients compared with normal individuals.

METHODS

We recruited 80 ESRD patients on hemodialysis and 70 healthy controls. History-taking, full examination, and complete blood count (CBC) were performed for all study subjects. Parvovirus B19 detection was performed through polymerase chain reaction (PCR), which included the QIAamp DNA Mini Kit for extracting DNA, which was amplified using TaqMan Universal Master Mix and detected using TaqMan MGB probes by real-time PCR using Rotor Gene Analyzer (6000).

FINDINGS

HD patients had a significantly higher frequency of B19V infection than the control group (p = .02). We also found that parvovirus B19-infected HD patients had significantly lower CBC values than uninfected patients.

CONCLUSION

The frequency of parvovirus B19 was significantly higher in HD patients and was associated with lower hematological parameters than in uninfected patients, suggesting a significant role of this virus in the pathogenesis of anemia and/or pancytopenia in ESRD.

Parvovirus B19 Infection Is Associated with Autoimmune Thyroid Disease in Adults

BACKGROUND

Autoimmune thyroid diseases are the most frequent autoimmune disorders, with a global prevalence of about 10%. Several mechanisms have been proposed to induce autoimmune thyroid responses by infectious agents. In this study, we aimed to evaluate the association between parvovirus B19 infection and autoimmune thyroid disorders.

METHODS

Adult patients with newly diagnosed Graves' disease (GD) and Hashimoto's thyroiditis (HT) and healthy euthyroid controls were recruited. Various clinical and biochemical parameters, including thyroid function tests and serum parvovirus B19 antibody level (IgG), were assessed and compared between the groups.

RESULTS

In this study, data from 404 cases with HT, 248 cases with GD, and 480 healthy individuals as a control group were analyzed. The prevalence of parvovirus B19 infection in patients with HT and GD and controls was 61.1%, 58.9%, and 47.1%, respectively. In the group of patients with HT, there was a significant positive correlation between the B19 IgG and TPOAb (r = 0.764, P < 0.001) and TgAb (r = 0.533, P < 0.001). Also, in patients with GD, the B19 IgG had a significant positive correlation with TPOAb (r = 0.779, P < 0.001) and TgAb (r = 0.467, P < 0.001).

CONCLUSIONS

Parvovirus B19 infection is commonly seen in patients with autoimmune thyroid disorders.

Parvovirus b19 infection in pregnancy - A review

Parvovirus B19 (B19V) is a widespread infection that may affect 1-5% of pregnant women, mainly with normal pregnancy outcome. Vertical transmission occurs in 33-51% of cases of maternal infection. B19V infection is an important cause of fetal morbidity (fetal anaemia and non-immune hydrops) and mortality, predominantly in the second trimester. Diagnosis of B19V infection requires a multi-method approach using mainly serology and PCR techniques. Severe fetal anaemia is managed with intrauterine transfusion with perinatal survival rates following intrauterine transfusion ranging from 67% to 85%. If fetal anaemia is mild, and considering that hydrops can spontaneously resolve, invasive therapy is not recommended and B19V complicated pregnancy may be non-invasively monitored by serial ultrasound examination and MCV-PSV measurements. As an alternative, intrauterine IVIG therapy has been described with successful treatment of fetal hydrops. No specific antiviral therapy or vaccine is presently available for B19V infection but efforts in the search for compounds inhibiting B19V replication are now being pursued. New virus-like-particle based parvovirus B19 vaccine candidates, produced by co-expressing VP2 and either wild-type VP1 or phospholipase-negative VP1 in a regulated ratio from a single plasmid inSaccharomyces cerevisiae have been developed and show sufficient promise to test in humans.

Serosurvey of parvovirus B19 and cytomegalovirus infections among female university students in Shiraz, Southern Iran

Infection with parvovirus B19 and cytomegalovirus (CMV) during pregnancy might lead to fetal infection, resulting in congenital abnormalities. This study aimed to investigate the frequency of IgM and IgG antibodies against parvovirus B19 and CMV in female university students in Shiraz, in Fars province, Southern Iran. In this cross-sectional study, 370 female university students were included. Blood samples were collected from each participant and tested for anti-parvovirus B19 and CMV IgG and IgM antibodies, using commercial ELISA kits. The mean age of the participants was 24 (±7)years. Out of 370 participants, 327 (88.4%) and 9 (2.4%) were positive for IgG and IgM antibodies against CMV. Moreover, 211 (57.0%) and 4 (1.1%) of the participants were respectively positive for IgG and IgM antibodies against parvovirus B19. The difference in CMV or parvovirus B19 seropositivity between different age groups was not statistically significant (P>0.05). The findings of our study showed that more than 50% of the female university students are seropositive to CMV and parvovirus B19 infections. It highlights the importance of health education and also the laboratory screening of females at childbearing age to reduce the risk of congenital infections resulting from these viral infections.

The role of Th17 cells in viral infections

The present review provides an overview of recent advances regarding the function of Th17 cells and their produced cytokines in the progression of viral diseases. Viral infections alone do not lead to virus-induced malignancies, as both genetic and host safety factors are also involved in the occurrence of malignancies. Acquired immune responses, through the differentiation of Th17 cells, form the novel components of the Th17 cell pathway when reacting with viral infections all the way from the beginning to its final stages. As a result, instead of inducing the right immune responses, these events lead to the suppression of the immune system. In fact, the responses from Th17 cells during persistent viral infections causes chronic inflammation through the production of IL-17 and other cytokines which provide a favorable environment for tumor growth and its development. Additionally, during the past decade, these cells have been understood to be involved in tumor progression and metastasis. However, further research is required to understand Th17 cells' immune mechanisms in the vast variety of viral diseases. This review aims to determine the roles and effects of the immune system, especially Th17 cells, in the progression of viral diseases; which can be highly beneficial for the diagnosis and treatment of these infections.

Human Parvovirus B19 Infection Among Blood Donors in North-East of Iran

Background: Human parvovirus B19 is a single-stranded DNA and non-enveloped virus which belongs to the Parvoviridae family. The virus spreads through respiratory secretions and perinatal blood. B19 may cause serious complications in patients with cellular immunodeficiency that have no detectable antibodies to B19, such as aplastic crises in solid organs. Objectives: The present study aimed to investigate the prevalence of parvovirus B19 and to evaluate the presence of B19 DNA among blood donors in Golestan Province. Methods: Sera of 400 blood donors in Golestan Province who were negative for HIV, HbsAg, and HCV were tested for both IgG and IgM anti-B19 virus antibodies using the ELISA method, following which all sera were tested for the presence of B19 DNA by semi-nested PCR. Results: 242 (out of 400) subjects (60.5%; 95% CI) were positive for anti-B19 IgG, and 158 were negative for IgG antibody (39.5%; 95% CI). Moreover, all asymptomatic blood donors were negative for anti-B19 IgM. No viral genome was found in serum samples of donors. Conclusions: Since no viral genome was found in the donors' serum samples and the relatively high prevalence of anti HPV- B19 IgG in blood donors, it can be concluded that the possibility of B19 transmission through blood transfusion is low. However, special caution should be taken when transfusing blood to the high-risk groups such as pregnant women, immune-deficient patients, and those with hematological problems, particularly regarding IgG anti- HPV- B19 antibodies (HPV- B19-safe).

A cross-sectional study on risk factors for infection with Parvovirus B19 and the association with anaemia in a febrile paediatric population in Ghana

Parvovirus B19 (B19V) occurs globally and can cause severe anaemia. The role of co-infections with Plasmodium falciparum (P. falciparum) has been controversially discussed. The study aimed to determine prevalence and severity of B19V infection, and the effect of co-infections on the risk for anaemia. Between November 2013 and April 2015 a total of 1186 hospital visits of children with fever admitted to a hospital in Ghana were recorded. Malaria, B19V and additional diagnostics for fever causes were performed. Recent B19V infection was defined as PCR and/or IgM positivity. Risk factors for a B19V infection and for anaemia were analysed. The prevalence of anaemia was compared between children with/without B19V infection, stratified for the presence of malaria. B19V IgM/PCR was positive in 6.4% (n = 76; 40 IgM + , 30 PCR + , 6 IgM + and PCR +). Among the B19V cases 60.5% had a simultaneous P. falciparum infection. B19V IgM positivity but not PCR positivity was associated with moderate-severe anaemia (OR = 2.6; 95%-CI: 1.3-5.3; P < 0.01 vs. OR = 0.9; 95%-CI: 0.4-1.8; P = 0.70). P. falciparum and IgM positive B19V infection were independent risk factors for anaemia with no evidence of effect modification. Our data show a significant association between B19V infection, defined as IgM but not PCR positivity, and moderate-severe anaemia. A multiplicative effect of B19V and P. falciparum infection was not found.

[Results of a study of parvovirus B19 (Parvoviridae, Parvovirinae, Erythroparvovirus, Primate erythroparvovirus 1) prevalence and circulation activity in socially significant categories of the population]

Currently, along with the increasing need of medical organizations for blood preparations, algorithms for laboratory testing of blood donors are not available for all infections with hemo-contact mechanism of transmission. A representative example is infection caused by parvovirus В19.

PURPOSE OF THE STUDY

The article presents the results of the original study, the purpose of which was to study the prevalence of antibodies to parvovirus B19 and the activity of the circulation of this virus in socially important categories of the population.

MATERIAL AND METHODS

The materials of the study were blood samples from blood donors of Saint Petersburg, as well as parvovirus В19 sequences isolated from DNA-positive plasma samples.

RESULTS AND DISCUSSION

According to the results of the laboratory examination, a high proportion of carriers of virus-specific IgG antibodies was found in studied group of donors, which confirms the previous infection of parvovirus B19 in them and illustrates the high prevalence of infection in this socially significant group. Based on the results of the blood preparations testing, the presence of parvovirus DNA В19 in a significant number of samples was determined by polymerase chain reaction method. This indicates an current parvovirus infection in the examined donors and points to a high epidemiological risk of the blood products obtained from them. Sequencing and phylogenetic analysis of a fragment of the VP1 gene demonstrated that the studied isolates belonged to А1 genotype and its subtype 1А2, which correlates with the genotypes of parvovirus В19 circulating in the European Union and Asia. In addition, two previously unknown В19 parvovirus isolates were isolated, the nucleotide sequences of which were deposited into the international GenBank database.

CONCLUSION

Based on the results of the study, it is justified to include testing of blood samples for markers of В19 parvovirus infection in existing algorithms of laboratory examination of donors, which will ensure prevention of hemo-contact infection of blood recipients with parvovirus В19.

Overall prevalence of human parvovirus B19 among blood donors in mainland China: A PRISMA-compliant meta-analysis

BACKGROUND

Human parvovirus B19 (B19V) infection exhibits a broad range of clinical outcomes. Blood transfusion is a common route of B19V transmission. However, information about the overall prevalence of B19V infection and B19V genotypes among blood donors in mainland China is lacking.

METHODS

This meta-analysis was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A literature search for studies reporting the B19V prevalence among blood donors in mainland China from 2000 to 2018 was performed. The prevalence of B19V was estimated through a meta-analysis of the relevant literature. A comprehensive meta-analysis program was used for data processing and statistical analysis.

RESULTS

Twenty-one eligible articles were included, involving 48,923 participants assessed for B19V-DNA, 12,948 participants assessed for anti-B19V immunoglobulin M (IgM), and 8244 participants assessed for anti-B19V immunoglobulin G (IgG). The analysis revealed the pooled estimates of the prevalence rates of B19V-DNA, anti-B19V IgM, and anti-B19V IgG among blood donors to be 0.7% (95% confidence interval [CI] 0.2-2.4%), 2.7% (95% CI 1.7-4.3%), and 33.6% (95% CI 28.2-39.4%), respectively. Moreover, phylogenetic analyses indicated that 142 of 169 (84.0%) B19V isolates belonged to Genotype 1.

CONCLUSIONS

The overall prevalence of B19V among blood donors is not high in mainland China, and most isolates belong to Genotype 1.

The human parvovirus B19/human immunodeficiency virus co-infection in healthy eligible voluntary blood donors at the Blood Transfusion National Center in Kinshasa

Introduction

Parvovirus B19 (PVB19) is one of several viruses transmissible by blood transfusion. Levels of exposure to PVB19 among HIV-infected voluntary blood donors are comparable to those among HIV-negative controls because, in blood donors, the PVB19 infection is transmitted mainly via the respiratory route. Thus, we hypothesize that the seroprevalence of PVB19 in HIV-positive blood donors is equal to the seroprevalence of PVB19 in HIV-negative blood donors. The objective of this study was to compare the seroprevalence of PVB19 between asymptomatic HIV-positive and HIV-negative blood donors.

Methods

A random sample of 360 eligible blood donors were firstly examined for HIV antibodies by using ELISA automaton and so were categorized as HIV-positive donors and HIV-negative donors. Then the two categories of donors were examined for PVB19 IgG and IgM by using ELISA kits. The seroprevalence of PVB19 in HIV-positive donors was compared to that of HIV-negative donors by using chi-square test or Fisher's exact test. All statistical analyzes were performed with SPSS 21.

Results

The prevalences of PVB19 IgG and IgM in HIV-positive blood donors were 92.1% (35 of 38) and 44.7% (17 of 38), respectively and those in control group were 89.1% (287 of 322) and 46.3% (149 of 322), respectively. But for both IgG and IgM the difference was not statistically significant (p > 0.05).

Conclusion

This research confirms our hypothesis: the seroprevalence of PVB19 in HIV-positive blood donors is equal to the seroprevalence of PVB19 in HIV-negative blood donors.

A Meta-Analysis on the Seroprevalence of Parvovirus B19 among Patients with Sickle Cell Disease

Background

Parvovirus B19 (B19 V) infection had been reported to be more frequent with serious clinical outcomes in patients with sickle cell disease (SCD) than in the general population. There is a wide variation in data among the existing literature regarding the seroprevalence of B19 V in patients with SCD. These data require further summary and analyses for better accuracy. This systematic review and meta-analysis was done to estimate the seroprevalence of B19 V in patients with SCD.

Methods

This study was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The databases of MEDLINE/PubMed, Virtual Health Library (VHL), ScienceDirect, Google Scholar, and OpenGrey were used for the systematic search. The random-effects model was used to estimate the pooled prevalence with the corresponding 95% confidence interval (CI) using OpenMeta Analyst software. Publication bias was estimated based on Begg's test, Egger's test, and examination of the funnel plot. Subgroup analyses and metaregression were used to explore the moderators of heterogeneity between studies.

Results

A total of 18 studies including 2890 patients were analyzed. The overall IgG seroprevalence of B19 V infection among patients with SCD was found to be 48.8% (95% CI 39.5%-58.0%). Evidence of publication bias was not detected. Evidence of acute viral infection detected by positive IgM antibodies among the screened SCD patients was found in 8.30% (95% CI 5.20%-11.4%) of them. There was a statistically significant association between seroprevalence of B19 V and geographical areas.

Conclusion

There was a high prevalence of B19 V in patients with SCD. Healthcare providers need to be aware of the magnitude of B19 V infection in patients with SCD to ensure effective management. This review could provide a comprehensive view of B19 V prevalence in this susceptible population.

Parvovirus B19 in South African blood donors

BACKGROUND

Parvovirus B19 (PVB19) is transmitted via transfusion of blood and blood products. PVB19 is resistant to viral inactivation methods, which poses a threat to blood safety. We investigated the prevalence of PVB19 antibodies and DNA in healthy blood donors from the South African National Blood Bank Service to evaluate the necessity of PVB19 DNA testing.

STUDY DESIGN AND METHOD

A retrospective analysis of 1500 residual plasma specimens from healthy blood donors from the SANBS repository were screened in mini-pools of 20 for PVB19 DNA using a quantitative polymerase chain reaction (PCR). Positive pools were resolved by individual viral load testing and screened for PVB19 immunoglobulin M (IgM) and immunoglobulin G (IgG) antibodies to correlate viral loads with serological status. PVB19 IgG prevalence was determined by testing 90 randomly selected specimens from the 1500 plasma specimens.

RESULTS

The prevalence of PVB19 IgG, IgM and IgG, and DNA was 62.2%, 0.06%, and 0.9%, respectively. Fourteen of the 1500 blood donor specimens received, had detectable PVB19 viral loads. Nine of the fourteen donors with detectable viral loads were PVB19 IgG seropositive. The PVB19 viral loads ranged from 1.81 to 5.32 log IU/mL. Four of the fourteen viraemic donors had a viraemia >10 ⁴ IU/mL.

CONCLUSION

We have demonstrated a low prevalence of PVB19 DNA in SANBS blood donors. The predominance of low-level viraemia and the presence of PVB19 antibodies, suggests that the risk of transfusion transmission of PVB19 among SANBS donors may be relatively low.

Evolutionary aspects of Parvovirus B-19V associated diseases and their pathogenesis patterns with an emphasis on vaccine development

Parvovirus B-19, a single human pathogenic member of the Parvoviridae family with it's small ssDNA and non-enveloped structure, is known to cause diseases in erythroid progenitor cells. But a wide range of clinical association of this virus with cells of non-erythroid origins has recently been discovered and many of those are being investigated for such association. Higher substitution rates in due course of evolution has been suggested for this cellular tropism and persistence. In this report, we have summarized the different disease manifestations of B-19 virus and have tried to find out a pattern of pathogenesis. Finally, we have focused on the vaccination strategies available against B-19 virus to correlate these with the mechanisms involved in various diseases caused by this virus.

Evidence of Human Parvovirus B19 Infection in the Post-Mortem Brain Tissue of the Elderly

After primary exposure, the human parvovirus B19 (B19V) genome may remain in the central nervous system (CNS), establishing a lifelong latency. The structural characteristics and functions of the infected cells are essential for the virus to complete its life cycle. Although B19V has been detected in the brain tissue by sequencing PCR products, little is known about its in vivo cell tropism and pathogenic potential in the CNS. To detect B19V and investigate the distribution of its target cells in the CNS, we studied brain autopsies of elderly subjects using molecular virology, and optical and electron microscopy methods. Our study detected B19V in brain tissue samples from both encephalopathy and control groups, suggesting virus persistence within the CNS throughout the host’s lifetime. It appears that within the CNS, the main target of B19V is oligodendrocytes. The greatest number of B19V-positive oligodendrocytes was found in the white matter of the frontal lobe. The number was significantly lower in the gray matter of the frontal lobe (p = 0.008) and the gray and white matter of the temporal lobes (p < 0.0001). The morphological changes observed in the encephalopathy group, propose a possible B19V involvement in the demyelination process.

Seroprevalence of parvovirus B19 in blood donors: the risks and challenges of blood transfusion in Zambia in the era of HIV/AIDS at the Kitwe Central Hospital, blood bank

BACKGROUND

Human Parvovirus (B19V) is a small, single-stranded, non-enveloped DNA virus which is pathogenic to humans causing a wide array of clinical complications which include erythema infectiosum, aplastic crisis and hydrops foetalis. It is generally harmless in healthy individuals but may be life threatening in immunocompromised individuals such as patients with sickle cell disease, cancer, HIV and pregnant women. It has been shown to be transmissible by blood transfusion but donor screening for the virus is not yet mandatory in most sub-Saharan African countries including Zambia.

MATERIALS AND METHODS

This was a cross-sectional study undertaken at the Kitwe Central Hospital, blood bank and Tropical Diseases Research Centre at Ndola Central Hospital. A total of 192 blood samples were screened for Ig M antibodies against parvovirus B19 by ELISA.

OBJECTIVES

The general objective of the study was to determine the seroprevalence of parvovirus B19 infections among healthy blood donors at the Kitwe Central Hospital blood bank. Specific Objectives were to detect parvovirus B19 Ig M antibodies in donor blood using serology and to analyse the age and sex distribution of parvovirus among blood donors.

RESULTS

The prevalence of parvovirus B19 Ig M in this study was 15.6%. The majority of the positive cases were in the age group 15-22 years (17.8%) but there was no statistical significance between occurrence of parvovirus and age ( p value=0.703). Prevalence in males was higher than in females that is 16.4% and 13.8%, respectively. The relationship between gender and parvovirus B19 occurrence was however not significant either (p value=0.516).

CONCLUSION

This study showed a 15.6% prevalence rate of acute Parvovirus B19 infections in blood donors at the Kitwe Central Hospital, blood bank. Studies with larger sample sizes are needed to validate these results.

Seroprevalence of human parvovirus B19 amongst North Indian blood donors - do current donor testing guidelines need a relook?

OBJECTIVES

The present study was aimed to find out the prevalence of parvovirus B19  amongst healthy blood donors and blood transfusion recipients so as to determine the feasibility of providing seronegative blood components to vulnerable recipients.

METHODS

A total of 1000 samples were studied which included 800 blood donors and 200 transfusion recipients.The transfusion recipients included 100 multitransfused patients and 100 non transfused controls.All samples were subjected to parvovirus B19 ELISA for IgG and IgM antibodies.

RESULTS

Of the 800 blood donors,663(82.9%) were voluntary while 137(17.1%) were replacement donors.The seroprevalence of B19V IgG antibodies among healthy blood donors was found to be 34.1% whilst that of IgM antibodies was 1.4%.The seroprevalence of B19 V IgG antibodies was found to be 28.4% in the age group 18-35 years and 42.1% in donors more than 35 years of age(p ≤ 0.01). The overall seroprevalence of IgG antibodies in multitransfused patients was 34% and IgM antibodies was 7.0%.The B19 V IgG prevalence was 20% in the transfused patients aged 0-20 years and 48% in patients above 20 years of age (p ≤ 0.05).

CONCLUSION

The moderately high seroprevalence of B19 V IgG in blood donors and patients suggests endemicity of infection.However, prevalence of B19 V IgM antibodies in blood donors is low.With the widespread use of pooled plasma derived medicinal products and recognition of severe pathological effects in susceptible recipients, transfusion transmission of B19 V has become a major concern in the past few decades.We suggest screening of blood units to identify B19 V IgM negative units for transfusion to selected patients.

Seroprevalence, molecular epidemiology and quantitation of parvovirus B19 DNA levels in Iranian blood donors

Human parvovirus B19 (B19) infection is common among blood donors, and healthy blood donors can transmit virus via transfusion. Due to resistance of B19 to viral inactivation methods, there is a potential concern regarding transfusion safety in blood products. We aimed to determine the seroprevalence, molecular epidemiology, and quantitation of B19 DNA levels in blood donors in Tehran, Iran. A total of 500 blood donors from Blood Transfusion Research Center were studied. ELISA was used for detection of B19 IgG and IgM and nested PCR was carried out for detection of B19 DNA. PCR products were subjected to direct sequencing. B19 viral load was determined by real time PCR. B19 IgG, IgM, and DNA were detected in 27.6, 2.6, and 1.2% of donors respectively. Ten samples (2%) were positive for both antibodies while in four cases (0.8%), B19 IgG and DNA detected simultaneously. One case had B19 IgM, IgG, and viremia concurrently. The titers of B19 DNA in four of six donors were more than 106 IU/mL (high level viremia) and all four cases had IgG simultaneously. All B19 isolates categorized in genotype 1A. Our findings indicated that prevalence of B19 DNA in Iranian blood donors was comparable with previous studies throughout the world. High level B19 viremia found in 0.8% of our donors and all viremic donors revealed neutralizing B19 antibody. Therefore implementation of a B19 screening test for each volunteer blood donor does not appear to be necessary but B19 testing for plasma‐derived products seems important in Iranian donors.

Incidence and progression of Parvovirus B19 infection and molecular changes in circulating B19V strains in children with haematological malignancy: A follow up study

The present study was planned to estimate the incidence of human Parvovirus B19 infection and understand its progression in children suffering with hematological malignancy. The circulating B19V genotypes and viral mutations occurring in strains of B19V over one-year period were also studied. Children with malignancies were enrolled consecutively and were followed up for one-year period. Serum sample was collected at the time of enrolment and each follow up visit and was tested for anti B19V IgG and IgM as well as for B19V DNA. At least one B19V DNA positive sample from each patient was processed for sequencing. For patients positive for B19V DNA >1 time and at least 6 months apart, last positive sample from the same patient was also sequenced to study the nucleotide change over time. We have found very high incidence of B19V infection (100%) in the study population. All the patients tested positive for at least one B19V infection parameter (either antibodies or DNA) at least once, over one year of follow up. Cumulative percent positivity of anti B19V IgG, anti B19V IgM and B19V DNA was 85.3%, 45.2% and 72.1% respectively. Genotype 3b was reported, with occasional nucleotide change over one year period. DNA clearance was delayed in spite of appearance of IgG antibodies. Appearance of IgM class of antibodies was either delayed or absent. To conclude, children with haematological malignancies have high incidence of B19V infection with late and short lived serological response and persistence of DNA for long duration.

The Impact of Emerging Infectious Diseases on Chinese Blood Safety

Emerging infectious diseases (EIDs) have always been one of the major threats to public health. Although the implementation of mandatory testing for 4 classical transfusion-transmitted infectious-human immunodeficiency virus, hepatitis B virus, hepatitis C virus, and syphilis-has reduced the transfusion risk of these pathogens, the potential threat of various EID agents and their constantly evolving variants to blood safety in China is not fully understood. This review presents 9 representative EID agents that are autochthonous and epidemic nationally or regionally in China. The epidemiologic status and distribution of these EID agents among donors and/or healthy populations are summarized. The potential risks of these EID agents to blood safety are discussed. The review also explores strategies to strengthen hemovigilance systems and studies to further evaluate the impact of EID agents on blood safety.

Frequency and Genotype of Human Parvovirus B19 among Iranian Hemodialysis and Peritoneal Dialysis Patients

OBJECTIVES

The aim of this study was to evaluate the frequency and genotype of human parvovirus B19 and its relation with anemia among Iranian patients under dialysis.

METHODS

Fifty hemodialysis (HD) and 33 peritoneal dialysis (PD) patients were enrolled. B19 IgG and IgM antibodies were assessed by ELISA, and the presence of B19 DNA was evaluated by nested PCR. PCR products were sequenced directly and phylogenetic analysis was performed.

RESULTS

In the HD group, the prevalence of B19 antibodies was 54% for IgG and 4% for IgM. B19 DNA was detected in 10% of the cases, and 10% showed B19 IgG and viremia simultaneously. In the PD group, the prevalence of B19 IgG and IgM was 57.6 and 0% respectively, whereas B19 DNA was found in 12.1% of the group. A total of 9.1% showed B19 IgG and viremia concurrently. There was no significant difference regarding anemia and B19 infection in either group. All B19 isolates were clustered in genotype 1A.

CONCLUSION

Our findings indicate that B19 infection plays no role in leading chronic anemia in dialysis patients. However, persistent B19 viremia and the circulation of the same strains in dialysis patients may indicate a potential risk for the contamination of dialysis equipment and nosocomial spread of B19 infection within dialysis units.

[Seroprevalence of human parvovirus B19 in children with fever and rash in the North of Tunisia]

The aim of the study is to evaluate the prevalence of specific antibodies anti-human parvovirus B19 (PVB19) immunoglobulin M (IgM) and IgG in children with fever and rash. This study involved 257 children aged from 7 months to 15 years with febrile rash unrelated to measles and rubella (seronegative for IgM). The sera were examined by immunoenzymatic assay. Detection of antibodies of PVB19 was done by enzyme-linked immunosorbent assay (Elisa). In our study, prevalence of immunoglobulin G (IgG) and IgM were 44 and 11.3%, respectively. Clinically, children with positive IgM serology had submitted an erythema infectiosum (13/29 cases), myocarditis (1 case), encephalitis (1 case), severe sickle cell anemia (7 cases), and immunocompromised (7 cases). The incidence rate of viral infection was 11.3%; most of the cases of PVB19 infection occurred between the months of May and August. Incidence was higher in the 10-15 years age group (21%). The prevalence of IgG antibody varied and increased with age, it rises from 38.2% in preschool children (19 months-4 years) to 53.5% in those aged between 4.5 and 15 years, reaching 58% in the 10-15 years age group. The four risk factors of PVB19 infection are: (1) those aged between 4.5 and 9 years, which is the most affected age group (P = 0.0018); (2) female gender in children aged between 19 months and 4 years (P = 0.037); (3) transfusion and (4) immune deficiency (P = 0.022 and P = 0.001, respectively). The study of the prevalence of PVB19 infection shows that viral infection is acquired early in childhood, increases with age; viral transmission is favored by the community life. Because of the widespread vaccination program against measles and rubella, the systematic search of PVB19 in front of eruptive fevers becomes important.

Parvovirus B19

Primary parvovirus B19 infection is an infrequent, but serious and treatable, cause of chronic anemia in immunocompromised hosts. Many compromised hosts have preexisting antibody to B19 and are not at risk. However, upon primary infection, some patients may be able to mount a sufficient immune response to terminate active parvovirus B19 infection of erythroid precursors. The most common consequence of B19 infection in the compromised host is pure red-cell aplasia, resulting in chronic or recurrent anemia with reticulocytopenia. Anemia persists until neutralizing antibody is either produced by the host or passively administered. Parvovirus B19 should be suspected in compromised hosts with unexplained or severe anemia and reticulocytopenia, or when bone-marrow examination shows either giant pronormoblasts or absence of red-cell precursors. Diagnosis is established by detection of B19 DNA in serum in the absence of IgG antibody to B19. In some cases, IgG antibody is detected but is not neutralizing. Anti-B19 IgM may or may not be present. Therapy includes any or all of the following: red-cell transfusion, adjustment in medications to restore or improve the patient’s immune system, and administration of intravenous immunoglobulin (IVIG). Following treatment, patients should be closely monitored, especially if immunosuppression is unchanged or increased. Should hematocrit trend downward and parvovirus DNA trend upward, the therapeutic options above should be revisited. In a few instances, monthly maintenance IVIG may be indicated. Caregivers should be aware that B19 variants, though rarely encountered, can be missed or under-quantitated by some real-time polymerase-chain reaction methods.

Parvovirus B19 Passive Transmission by Transfusion of Intercept® Blood System-Treated Platelet Concentrate

BACKGROUND

Pathogen reduction methods for blood components are effective for a large number of viruses though less against small, non-enveloped viruses such as Parvovirus B19 (B19V). This article describes the passive transmission by transfusion of two B19V-contaminated pooled platelet concentrates (PCs) which were treated with the Intercept® blood pathogen reduction system.

CASE REPORTS

Two transfusion cases of B19V-contaminated Intercept-treated pooled PCs were described. Due to the analysis delay, the PCs were already transfused. The viral content of each donation was 4.87 × 10(10) IU/ml in case 1and 1.46 × 10(8) IU/ml in case 2. B19V (52 IU/ml) was detected in the recipient of the case 1 PC, whereas no virus could be detected in the case 2 PC recipient. A B19V IgM response and a transient boost of the underlying B19V IgG immune status and was observed in recipient 1. Recipient of the case 2 PC remained B19V IgG- and IgM-negative. B19V DNA sequence and phylogenetic analysis revealed a 100% homology between donor and recipient.

CONCLUSION

This report describes passive B19V transmission by a PC with very high B19 viral load which elicited a transient boost of the B19V immunity, but not by a PC with a lower B19V content, suggesting that there is a B19 viral load threshold value at which B19V inactivation is exceeded.

No evidence of persistent parvovirus B19 viremia among Iranian patients with HIV after a 1-year follow-up

Recent studies have demonstrated that, in common with other latent viruses, parvovirus B19 infection can be controlled by the host immune response but may persist in some places such as the bone marrow. Persistent B19 infection has been found in both immunocompetent and immunocompromised individuals, such as patients infected with human immunodeficiency virus (HIV). However, there is limited data regarding long-term B19 viremia in HIV patients. In this study, we investigated virological and hematological findings, and also the clinical outcome, of seven cases of HIV/B19 coinfection (confirmed by PCR) after one year. These cases were provided from a previous study on patients with HIV infection that found B19 DNA in 13 cases. Seven of these 13 patients were available after 1 year, and we retested them for B19 viremia and B19-specific antibodies. B19 IgG was tested by ELISA, and B19 DNA was assessed by nested PCR. Anemia was not observed in these cases. All subjects had cleared viremia, but B19 IgG seroconversion occurred in two cases. No significant changes in CD4 and hemoglobin occurred. The results of this study indicate that B19 infection in HIV patients is a subtle infection and that B19 viremia is not a long-term event.

Viral arthritis

Acute-onset arthritis is a common clinical problem facing both the general clinician and the rheumatologist. A viral aetiology is though to be responsible for approximately 1% of all cases of acute arthritis with a wide range of causal agents recognised. The epidemiology of acute viral arthritis continues to evolve, with some aetiologies, such as rubella, becoming less common due to vaccination, while some vector-borne viruses have become more widespread. A travel history therefore forms an important part of the assessment of patients presenting with an acute arthritis. Worldwide, parvovirus B19, hepatitis B and C, HIV and the alphaviruses are among the most important causes of virally mediated arthritis. Targeted serological testing may be of value in establishing a diagnosis, and clinicians must also be aware that low-titre autoantibodies, such as rheumatoid factor and antinuclear antibody, can occur in the context of acute viral arthritis. A careful consideration of epidemiological, clinical and serological features is therefore required to guide clinicians in making diagnostic and treatment decisions. While most virally mediated arthritides are self-limiting some warrant the initiation of specific antiviral therapy.

No Definite Association between Human Parvovirus B19 Infection and Behçet Disease

BACKGROUND

The etiology of the Behçet disease (BD) has remained obscured. There have been studies to show the association of BD to infections like herpes simplex, hepatitis, and parvovirus B19 however, the findings are rather controversial.

MATERIALS AND METHODS

We selected 55 patients with the best matched symptoms of BD and measured the loads of B19 DNA in their plasma by quantitative real time PCR and verified their seropositivity by ELISA. All findings were compared to the results from 42 healthy persons.

RESULTS

Patients showed a wide spectrum of BD symptoms. Serologic studies showed high prevalence of B19 IgG among the tested patients which was not statistically different with the healthy population (72.7% vs. 85.7%, respectively). Similarly, the prevalence of B19 IgM between patients and controls was not different (18% vs. 11.9%, respectively). No correlation was found between the presence of anti-B19 antibodies and the clinical observations. Only one person from the patient and control groups had detectable levels of B19 DNA without any difference or correlation with the disease symptoms.

CONCLUSION

Our data could not establish an association between B19 parvovirus infection and Behçet disease, although there have been reports of such correlation. Nevertheless, there might be indirect relation in genetically susceptible individuals after viral infections. More studies on designed animal models and surveys on patients should be done to resolve this controversy.

Prevalence and Viral Load of Human Parvovirus B19 (B19V) Among Blood Donors in South-East Brazil

The infection of human parvovirus B19 (B19V) is a common event in the general population, including volunteer blood donors. In some cases it can be asymptomatic and can remain persistent for a long period of time. The objective of this study was to examine the B19V DNA prevalence and viral load in first-time volunteer blood donors. Blood samples were collected from 91 primary blood donors at the Regional Blood Center of Ribeirão Preto, Southeast Brazil. Viral detection and quantitation was performed by an in-house TaqMan(®) real-time PCR with high sensitivity. B19V DNA was detected in one male blood donor (1.0 %) and was characterized by a very low viral load (537.36 copies/mL). Our studies demonstrate that B19V DNA at low titer may be present in apparently healthy individuals. Sensitive molecular diagnostic tools can be applied for the screening of fresh blood derived products in order to prevent transfusion-transmitted B19V infection.

Frequency and genotype of human parvovirus B19 among Iranian patients infected with HIV

The human parvovirus B19 (B19) usually causes a subclinical infection in immunocompetent individuals. Whereas immunocompromised individuals such as patients infected with HIV are at risk of persistent anemia due to B19 infection. Only few studies have been carried out on distribution and molecular epidemiology of B19 in Iran. We aimed to determine the frequency and genotype of B19 among Iranian patients infected with HIV. We conducted a survey on 99 HIV patients and 64 healthy controls. IgG and IgM antibodies against B19 were detected by ELISA and B19 DNA was assessed by nested PCR. PCR products were subjected to direct sequencing and classified after phylogenetic analysis. The prevalence of B19 immunoglobulin was 11.1% for IgG and 1% for IgM. B19 DNA was detected in 13.1% of cases. The prevalence of B19 IgG, IgM, and DNA in control group was 25%, 1.6%, and 9.4%, respectively. B19 IgG was significantly lower in HIV group than in normal controls. There was no significant difference regarding anemia between cases and controls. All sequenced B19 isolates belonged to genotype 1A with low genetic diversity. Our findings indicated that in the HAART era, the importance of B19 infections in HIV patients may be limited whereas persistent B19 viremia in the circulation of healthy controls raises a potential concern in blood donations.

Fetal thrombocytopenia in pregnancies with fetal human parvovirus-B19 infection

OBJECTIVE

Fetal infection with human parvovirus B19 (hParvo-B19) has been associated mainly with fetal anemia, although data regarding other fetal hematologic effects are limited. Our aim was to assess the rate and consequences of severe fetal thrombocytopenia after fetal hParvo-B19 infection.

STUDY DESIGN

We conducted a retrospective study of pregnancies that were complicated by fetal hParvo-B19 infection that underwent fetal blood sampling (FBS). The characteristics and outcomes of fetuses with severe thrombocytopenia (<50 × 10(9)/L) were compared with those of fetuses with a platelet concentration of ≥50 × 10(9)/L (control fetuses). Fetuses in whom 3 FBSs were performed (n = 4) were analyzed to assess the natural history of platelet levels after fetal hParvo-B19 infection.

RESULTS

A total of 37 pregnancies that were affected by fetal hParvo-B19 infection were identified. Of the 29 cases that underwent FBS and had information regarding fetal platelets, 11 cases (38%) were complicated by severe fetal thrombocytopenia. Severely thrombocytopenic fetuses were characterized by a lower hemoglobin concentration (2.6 ± 0.9 g/dL vs 5.5 ± 3.6 g/dL; P = .01), lower reticulocyte count (9.1% ± 2.8% vs 17.3% ± 10.6%; P = .02), and lower gestational age at the time of diagnosis (21.4 ± 3.1 wk vs 23.6 ± 2.2 wk; P = .03). Both the fetal death rate within 48 hours of FBS (27.3% vs 0%; P = .02) and the risk of prematurity (100.0% vs 13.3%; P < .001) were higher in fetuses with severe thrombocytopenia. Fetal thrombocytopenia was more common during the second trimester but, in some cases, persisted into the third trimester. Intrauterine transfusion (IUT) of red blood cells resulted in a further mean decrease of 40.1% ± 31.0% in fetal platelet concentration.

CONCLUSION

Severe fetal thrombocytopenia is relatively common after fetal hParvo-B19 infection, can be further worsened by IUT, and may be associated with an increased risk of procedure-related fetal loss after either FBS or IUT.

Characterization of Markers of the Progression of Human Parvovirus B19 Infection in Virus DNA-Positive Plasma Samples

BACKGROUND

Accurate characterization of the infection stage in parvovirus B19(B19V)-positive plasma donations would help establish the donation deferral period to contribute to a safe fractionation pool of plasma.

METHODS

Viral DNA load of 74 B19V DNA-positive plasma samples from whole blood donations was determined by titration using nucleic acid testing. Markers of cellular (neopterin) and humoral (B19V-specific IgM and IgG) immune response were determined by ELISA in 32 B19V DNA-positive samples and in 13 B19V DNA-negative samples. The infection progression profile was estimated according to B19V DNA load and the presence of immune response markers.

RESULTS

B19V DNA load in the 74 samples was 10(6)-10(13) IU/ml. The distribution of 14 out of 32 selected B19V DNA-positive samples plus 2 B19V DNA-negative samples with no immune response marker followed along an upward curve according to B19V DNA load. After the peak, the distribution of 18 immune marker-positive samples followed along a downward curve according to their B19V DNA load and was grouped as follows: neopterin (n = 4), neopterin+ IgM (n = 8), neopterin + IgM + IgG (n = 3), IgM + IgG (n = 2), IgM (n = 1). There were 11 B19V DNA-negative IgG-positive samples.

CONCLUSION

This study of B19V-DNA load and levels of neopterin, IgM, and IgG allows for reliable characterization and distribution into the different stages of B19V infection.

Congenital Parvovirus B19 Infection: Persistent Viremia and Red Blood Cell Aplasia

We describe a case of fetal parvovirus B19 infection resulting in preterm birth and leading to hydrops fetalis requiring multiple in utero transfusions. The infant developed chronic postnatal anemia responsive to intravenous immunoglobulin therapy. Serum viral load decreased after immunoglobulin treatment but remained detectable for over 1 year.

Th17-related cytokines in systemic lupus erythematosus patients with dilated cardiomyopathies: a possible linkage to parvovirus B19 infection

Dilated cardiomyopathies (DCM) are a major cause of mortality in patients with systemic lupus erythematosus (SLE). Immune responses induced by human parvovirus B19 (B19) are considered an important pathogenic mechanism in myocarditis or DCM. However, little is known about Th17-related cytokines in SLE patients with DCM about the linkage with B19 infection. IgM and IgG against B19 viral protein, and serum levels of Th17-related cytokines were determined using ELISA in eight SLE patients with DCM and six patients with valvular heart disease (VHD). Humoral responses of anti-B19-VP1u and anti-B19-NS1 antibody were assessed using Western blot and B19 DNA was detected by nested Polymerase Chain Reaction (PCR). Levels of interleukin (IL)-17, IL-6, IL-1β, and tumor necrosis factor (TNF)-α were significantly higher in SLE patients with DCM (mean ± SEM, 390.99±125.48 pg/ml, 370.24±114.09 pg/ml, 36.01±16.90 pg/ml, and 183.84±82.94 pg/ml, respectively) compared to healthy controls (51.32±3.04 pg/ml, p<0.001; 36.88±6.64 pg/ml, p<0.001; 5.39±0.62 pg/ml, p<0.005; and 82.13±2.42 pg/ml, p<0.005, respectively). Levels of IL-17 and IL-6 were higher in SLE patients with DCM versus those with VHD (both p<0.01). Five (62.5%) of DCM patients had detectable anti-B19-NS1 IgG and four (50.0%) of them had anti-B19-VP1u IgG, whereas only one (16.7%) of VHD patients had detectable anti-B19-NS1 IgG and anti-B19-VP1u IgG. Serum levels of IL-17, IL-6 and IL-1β were markedly higher in SLE patients with anti-B19-VP1u IgG and anti-B19-NS1 IgG compared to those without anti-B19-VP1u IgG or anti-B19-NS1 IgG, respectively. These suggest a potential association of B19 with DCM and Th17-related cytokines implicated in the pathogenesis of DCM in SLE patients.

Development and evaluation of baculovirus-expressed Chikungunya virus E1 envelope proteins for serodiagnosis of Chikungunya infection

Population-based serosurveillance studies provide critical estimates on community-level immunity and the potential for future outbreaks. Currently, serological assays, such as IgG enzyme-linked immunosorbent assays (ELISAs) and indirect immunofluorescence tests (IIFT) based on the inactivated whole virus are used to determine past Chikungunya virus (CHIKV) infection. However, these commercially available tests have variable sensitivities. To develop and evaluate recombinant based CHIKV-specific IgG antibody capture ELISAs (GAC-ELISAs), baculoviruses carrying wild-type (E1-A226, named WT) or mutant (E1-A226V, named MUT) E1 envelope protein genes of CHIKV were generated. The seroreactivity of recombinant CHIKV WT and MUT envelope proteins were determined using residual blood, collected from CHIKV-confirmed patients. The sensitivities of both recombinant CHIKV envelope proteins were 83.0% as measured by GAC-ELISAs. The specificities of both recombinant proteins were 87.8%. These GAC-ELISAs were also able to detect the persistence of anti-CHIKV IgG antibodies up to 6 months after the disease onset, together with rise in sensitivities with increasing time. These results suggest that the baculovirus purified recombinant CHIKV envelope proteins react with anti-CHIKV IgG antibodies and may be useful in population-based seroprevalence surveys. In addition, these GAC-ELISAs offer good diagnostic value to determine the recent/past CHIKV infection status in non-endemic populations.

Seroprevalence of parvovirus B19 antibodies and evidence of viremia among Nigerian patients with sickle cell anemia

Clinical, biochemical and molecular evidence for the sickle cell anemia (SCA) crisis in Nigerian patients arising from parvovirus b19 infection remains inadequate. This study determined the prevalence and correlates of anti-parvovirus b19 antibodies in a population of SCA patients and non-SCA healthy controls in Lagos, Nigeria. In this prospective cross-sectional study, we enrolled 73 confirmed SCA patients from 5 district hospitals in Lagos and 81 sex and age-matched non-SCA healthy controls. Serum sample from each study participant was screened for anti-parvovirus b19 by ELISA and PCR techniques. Standard biomedical assays were also done. Anti-parvovirus b19 IgM and IgG antibodies were detected in 22 (14.3%) and 97 (62.9%) of the 154 sera screened, 13 (17.8%) and 45 (61.6%) in SCA patients; 9 (11.1%) and 52 (64.2%) in non-SCA controls. The overall seronegativity rate was 19.5%. Parvovirus B19 DNA was found in 2 (11.1%) of the 18 IgM seropositive SCA serum samples screened. On the whole, parvovirus b19 infection was more commonly asymptomatic in non-SCA controls but caused significant elevation in liver enzymes in infected SCA patients (P < 0.05). The risk of acute parvovirus b19 infection increased 65 times during unsteady state among the SCA patients. Although no deaths of infected patients were recorded during the study, age below 12 years, hospitalization and overcrowded environment were risk factors for infection. We conclude that parvovirus b19 is common in SCA patients, incurring greater susceptibility to infections.